I can widen you can widen he can widen we can widen you can widen they can widen
V-ing form
I can be widening you can be widening he can be widening we can be widening you can be widening they can be widening
Perfect
I can have widened you can have widened he can have widened we can have widened you can have widened they can have widened
V-ing perfect
I can have been widening you can have been widening he can have been widening we can have been widening you can have been widening they can have been widening
Negation
Simple form
I can't widen you can't widen he can't widen we can't widen you can't widen they can't widen
V-ing form
I can't be widening you can't be widening he can't be widening we can't be widening you can't be widening they can't be widening
Perfect
I can't have widened you can't have widened he can't have widened we can't have widened you can't have widened they can't have widened
V-ing perfect
I can't have been widening you can't have been widening he can't have been widening we can't have been widening you can't have been widening they can't have been widening
Interrogative form
Simple form
can I widen? can you widen? can he widen? can we widen? can you widen? can they widen?
V-ing form
can I be widening? can you be widening? can he be widening? can we be widening? can you be widening? can they be widening?
Perfect
can I have widened? can you have widened? can he have widened? can we have widened? can you have widened? can they have widened?
V-ing perfect
can I have been widening? can you have been widening? can he have been widening? can we have been widening? can you have been widening? can they have been widening?
Interro-negative form
Simple form
can't I widen? can't you widen? can't he widen? can't we widen? can't you widen? can't they widen?
V-ing form
can't I be widening? can't you be widening? can't he be widening? can't we be widening? can't you be widening? can't they be widening?
Perfect
can't I have widened? can't you have widened? can't he have widened? can't we have widened? can't you have widened? can't they have widened?
V-ing perfect
can't I have been widening? can't you have been widening? can't he have been widening? can't we have been widening? can't you have been widening? can't they have been widening?